Fuse construction



April 12, 1938. A. G. STEINMAYER FUSE CONSTRUCTION Filed Dec. 4, 1935 INVENTOR. 5/4 9 fazkz/r/ayafl 5% fiZCJ I QRNEY.

Patented A r. 12, 1938- I 2,113,632

UNITED STATES PATENT OFFICE FUSE CONSTRUCTION Alwin G. Steinmayer, Milwaukee, Wis., assignor to Line Material Company, South Milwaukee, Wis., a corporation of Delaware Application December 4, 1935, Serial No. 52,792 16 Claims. (01. 200-417) This invention relates to a fuse construction. j ent t rminal e e thereby increasing the Objects of this invention are to provide a very Separation and additionally giving a V b e nsimple type of fuse construction which may be dication that the fuse has blown, the construction used in any capacity but is eminently suitable for being such that only one contact is required for use as a secondary fuse. the fuse tube, the free or open end of the fuse It is well known that where very small amperage tube being without a contact member. primary link fuses are used when fusing a trans- Further objects are to provide a construction former for instance, that it is usually the practice in which a relatively heavy spring pressure may to use nothing smaller than a 3-ampere fuse for be applied to assist in maintaining contact beexample, with the result that there is often over tween the fuse and a contact carried by the fuse 10 fusing of the smaller transformers, particularly tube and also acting in a capacity to move the fuse of the 13,000 volt class, and secondary fuses are tube or fuse assembly f Operative to inoptherefore necessary for overload protection. erative position, preferably assisting the action of Additionally, it is advisable 'to use secondary r v the Contact Pressure being l iv ly hi h fuses where there are grouped secondaries of the and the spring itself, in addition to the terminal 5 transformers to prevent outage cf the entire member, furnishing a conducting path from one group in case of failure of a single transformer. end of the fuse link to the adjacent terminal This invention is designed to provide a. 5115- member, the construction being such, however, pension type fuse which does not require any that although a relatively high contact pressure room on the cross arm of a pole, for example, is provided, nevertheless a relatively small strain but instead may be employed directly in the secis imposed on the fuse link. The construction is ondary line, thus minimizing the space requiresuch that although a short fuse tube may be emment, and which may be placed in any position, ployed if desired, the leakage path is great after either horizontally, vertically or in 'an angu ar the fuse has dropped open so that the chance of position. arcing over even with a very short tube is very 25 In general, this invention is an improvement much lessened. 7 over that disclosed in the copending application of An embodiment of the invention is shown in the Ramesis Alfonso Hammack for a Fuse construcaccompanying drawing, in which: tion, filedNovember 8, 1935, Serial No. 48,837. Figure 1 is a side elevation of the drop-out sus- In some previous constructions of suspension pension use a t appears w e in position, parts 30 fuses it has been the practice to provide a sepabeing broken away and in section, the fuse tube rate insulating block which acts as a mounting being shown in dotted lines as it appears after the member for the fuse link. fuse has blown.

This invention, however, has for its further Figure 2 is a fragmentary sectional view object the provision of a suspension fuse in through the fuse tube taken on the line 22 of 35 which the strain member also serves as a spacing Figure 1, with parts broken away and in section. member for the fuse link, and in which the sus- Figure 3 is a sectional view through the insulapension member, which may be of a. porcelain tor, the line wires being omitted, such view corbody portion, for example, is so joined to the line sp g to a S t n 011 t line 40 wires that the porcelain is placed under compres- Figure 1. 40 sion, and in which no strains due to the pull of Referring to the drawing, it will be seen that the line wires are imposed upon the fuse link or an insulator l preferably of porcelain has been fuse member, such member being held spaced with provided and has transversely extending aperrelation to the line wires and being so held that tures 2 and 3 therethrough for the reception of it may be readily renewed. the line wires 4 and 5. These line wires lie in 45 Further objects are to provide a suspension fuse diametrically opposed grooves arranged in pairs construction of the drop-out type in which a fuse and formed in the insulator I and indicated by assembly, which may include a fuse tube and a the reference characters 6 and I, the pair of fuse link for instance, is movably, preferably ooves 5 g g w t aperture 2 and the pivotally supported from theporcelain member pair of grooves l aligning with the aperture 3. 50

preferably being carried by one of the terminal The line wires are interlooped, as is apparent members, in which the free end of the fuse tube from Figure 1, that is to say, the line wire 4 lies is held in place by the fuse link and is released within the groove 1 and passes through the aperwhen the fuse link is ruptured, allowing the free ture 3, a t line Wire 5 lies Within the groove mi end of the fuse tube to move away from the ad- 6 and passes through the aperture 2 so that they are interlinked and thus place the porcelain or other insulating member I under compression.

Terminal members 8 and 9 are secured to the main insulator or body portion I in any suitable manner, as by means of the screws in cemented in place at the end faces of the body portion i, preferably lock washers and nuts being provided to lock the terminal members 8 and 9 rigidly to the end faces of the body portion l.

The terminal member 8 is provided with a screw Ii and nut l2 for locking the bared end of the conductor 4 to the terminal member 8, a suitable washer being employed as indicated.

The terminal member 8 continues downwardly and is provided with an offset looped portion or bearing portion i3 and continues outwardly in a horizontal portion [4 with an upstanding finger or end l5 for a purpose which will hereinafter appear. A relatively heavy leaf spring I5 is clamped between the body portion l andthe terminal member 8 and projects-downwardly, as shown in Figure 1.

A fuse tube assembly, consisting of a fuse tube i'I formed of insulating material and provided with an open outer end slightly internally rounded, as indicated at I8, is provided with a contact or head ii! at its pivoted end. This contact i9 is in reality a. cap with an aperture therethrough and is screwed or otherwise secured 'to the fuse tube IT. The contact member [9 is provided with downwardly extending spaced arms 20 which carry a pivot pin 2| loosely fitting within the looped portion or hinge portion l3 of the terminal member 8, as shown clearly in Figures 1 and 2.

The fuse tube assembly also includes a fuse link which may be of any construction. For example-it may be provided with a flexible leader 22 and with a button head 23 and an intermediate, fusible preferably reduced portion 24.

This fuse link is passed through the contact l9 and the button head bears either directly against the contact or against a washer 25, if so desired.

The free end of the relatively heavy spring 18 bears directly against the button head 23 of the fuse link and affords a relatively high contact pressure to insure good electrical contact, and the spring, therefore, as well as the terminal member 8, affords a. direct current path to the line line conductor 4.

The terminal member 9 carries a screw 26 and a nut 21 which locks thebared end of the line wire or conductor 5 to the terminal member 9, a washer being preferably employed as indicated. The screw 26 may be longer than the screw II, as shown in Figure 1, and carries a thumb nut 28 which releasably receives the free end of the fuse link, as shown, so as to permit ready re-fusing after the fuse has blown.

It is to be noted that due to the peculiar leverage effect, the contact pressure from the spring 16 may be high, but nevertheless the actual pull on the fuse link is relatively small.

When the fuse blows, the ruptured link releases the fuse tube assembly and the fuse tube rocks into the dotted line position under the influence of gravity, but primarily under the influence of the relatively heavy spring I 8. This spring insures a positive motion of the fuse tube from operative to inoperative position.

The free end of the fuse tube moves to a point widely spaced from the terminal member 9 and thus provides a wide spacing of the parts, or, in other words, -a long leakage path, greatly lessening the chance of arcing or of any slow leak- Additionally, the discharge of the heated gases and volatilized metal is away from the body portion and there is no chance of carbonizing or of the forming of a metal coating from condensed ily inserted and the free end thereof may be clamped beneath the thumb nut 28 after the fuse tube assembly has been rocked back into place.

It is apparent that in re-fusing, the unscrewing of the thumb nut 28 will not loosen the attachment of the corresponding line wire. Also it is apparent that this device may be most easily refused and put back into service.

It is to be noted further that the invention provides a porcelain or other insulating body portion which is preferably held in compression and carries a drop-out fuse structure.

It is also apparent that these suspension fuses may be placed horizontally, vertically or at any angle desired, and that although the fuse tube assembly is preferably placed directly below the body portion, it nevertheless may be placed in another position than that shown in Figure 1. These suspension fuses require no mounting or space on the cross arm of a pole, for instance, but are held directly by the line wires, consequently minimizing the space requirement.

Although the invention has been described in considerable detail, it is to be understood that the description is intended as illustrative rather than limiting, as the invention nfay be variously embodied and is to be interpreted as claimed.

I claim:

1. A suspension fuse construction comprising a body portion formed of insulating material and having spaced apertures for the reception of looped conductors with the loop of one conductor interlinking the loop of the other conductor, terminal members carried by said body portion and electrically connected to said conductors, and a drop-out fuse assembly normally electrically connecting said conductors, said drop-out fuse assembly including an insulating tube enclosing a fuse link and located below said body portion.

2. A suspension fuse construction comprising a body portion formed of insulating material and having spaced apertures for the reception of looped conductors with the loop of one conductor interlinking the loop of the other conductor, terminal members carried by said body portion and electrically connected to said conductors, a dropout fuse assembly normally electrically connectlng said conductors, and a spring biasing said fuse assembly towards drop-out movement.

3. A fuse construction comprising a body portion formed of insulating material and having means for the reception of conductors, terminal members carried by said body portion and electrically connected to said conductors, and a dropout fuse assembly including an insulating movable portion and a fuse link carried by said movable portion and normally electrically connecting said terminal members, said fuse link restraining 4. A fuse construction comprising a body portion formed of insulating material and having means for the reception of conductors, terminal members carried by said body portion and electrically connected to said conductors, a drop-out fuse assembly including an insulating movable portion and a fuselink carried by said movable portion and normally electrically connecting said terminal members, said fuse link restraining said movable portion from drop-out movement and releasing said movable portion when said fuse fu'se link is ruptured, said movable portion having a contact at only one end, and a spring binding against said fuse link and electrically connected to one of said terminal members, said spring biasing said fuse assembly towards dropout movement. I

5. A fuse structure comprising an insulating body portion, a first and a second terminal member carried by said body portion and projecting therefrom, means carried by said terminal members for receiving conductors, an insulating fuse tube having a contact at one end provided with an aperture and pivotally mounted upon the first of said terminal members, the other end of said fuse tube being normally positioned adjacent the second of said terminal members and having an open end, a headed fuselink extending through the aperture in said contact with the head of the fuse link located on the outer side of said contact, and means carried by the second terminal member for removably locking the fuse link to said second terminal member to hold said fuse tube in position against rocking motion, said first terminal member including spring means bearing against the head of said fuse link and producing contact pressure and tending to rock said fuse tube towards inoperative position away from said second terminal member.

6. A fuse construction comprising an insulating body portion having a. first and a second terminal member projecting therefrom, means carried by said terminal members for the reception of conductors, said first terminal member having a hooked portion, an insulating fuse tube having an open end and having a contact carried by the other end of said fuse tube and provided with a lateral extension removably hooked into the hooked portion of said first terminal member, a headed fuse link projecting through the contact of said fuse tube with the head located on the outer side of said contact, said fuse link extending throughsaid fuse tube and out of the open end thereof, and means carried by said second terminal member for removably locking the projecting end of said fuse link to said second terminal member to normally hold said fuse tube in operative position, said first terminal member including relatively heavy spring means for exerting contact pressure upon the head of said fuse link and tending to rock said fuse tube towards inoperative position.

'7. A fuse construction comprising an insulating body portion having a first and a second terminal member projecting therefrom, means carried by said terminal members for the reception of conductors, said first terminal member having a hooked portion, a fuse tube having an open end and having a contact carried by the other end,

of said fuse tube and provided with a lateral oilset removably hooked into the hooked portion of said first terminal member, a headed fuse link projecting through the contact of said fuse tube with the head located on the outer side of said contact, said fuse link extending through said fuse tube and out of the open end thereof, and means carried by said second terminal member for removably locking the projecting end of said fuse link to said second terminal member to normally hold said fuse tube in operative position,

said first terminal member including relatively heavy spring means for exerting heavy contact pressure upon the head of said fuse link and tending to rock said fuse tube towards inoperative position, the offset from the contact of said fuse tube being relatively short in comparison to the length of said fuse tube, whereby the relatively heavy contact pressure is translated into a relatively light pull on the fuse link.

' 8. A fuse construction comprising an insulating body portion having a first and a second terminal member projecting therefrom, means carried by said terminal members for the reception of conductors, said first terminal member having a. hooked portion, a. fuse tube having an open end and having a contact carried by the other end of said fuse tube and provided with a lateral extension removably hooked into the hooked portion of said first terminal member, a headed fuse link projecting through the contact of said fuse tube with the head located on the outer side of said contact, said fuse link extending through said fuse tube and out of the open end thereof, and means carried by said second terminal member for removably locking the projecting end of said fuse link to said second terminal member to normally hold said fuse tube in operative position, said first terminal member including spring means for exerting contact pressure upon the head of said fuse link and tending to rock said fuse tube towards inoperative position, said hooked por tion of said first terminal member having means to prevent the inadvertent detachment of the fuse tube from said first terminal member when said fuse tube rocks to inoperative position.

9. A suspension fuse construction comprising an insulating body portion having means for the reception of conductors, whereby said body portion may be suspended, a first and a second terminal member projecting from said body portion and having means for electrical connection to said conductors, a fuse tube assembly pivotally mounted upon said first terminal member and having an open end normally located adjacent said second terminal member, the other end of said fuse tube being closed when said fuse tube is in operative position, an expulsible conductor carried within said fuse tube and secured to said second terminal member, and current responsive means for releasing said fuse tube assembly upon the occurrence of an overload.

10. A suspension fuse construction comprising an insulating body portion having conductor receiving means for suspending said body portion from the conductors, a first and a second terminal member carried by said body portion and having means for electrical connection to said conductors, a fuse tube assembly removably pivotally carried by said first terminal member and having an open end normally located adjacent said second terminal member, the other end of said fuse tube being closed when said fuse tube is in operative position, means tending to rock said fuse tube assembly to move the open end thereof from ad-- jacent said second terminal member, an expulsible conductor carried by said fuse tube assembly and removably locked to said second terminal member, and current responsive means for releasing said fuse tube assembly upon the occurrence of an overload.

11. A fuse construction comprising a. body portion, terminal members carried by said body por-' tion and having means for electrical connection to conductors, at least one of said terminal members being stationary, a drop-out fuse assembly normally connecting said terminal members and having one end movable away from its corresponding terminal member, and a fuse link carried within said fuse tube and projecting outwardly therefrom and directly connected to said stationary'terminal member for normally holding the movable end .of said fuse tube against motion away from the corresponding terminal member, the other end of said fuse link having'a headed portion normally closing said fuse tube.

12. A fuse construction comprising a body portion, an expulsion fuse assembly including an insulating fuse tube open at one end, a fuse link having a head closing the other end of said fuse tube, a first terminal member carried by said body portion and pivotally supporting said fuse tube and exerting spring pressure against the head of said fuse link tending to rotate said fuse tube and holding the head in sealing relation to said fuse tube, and a second terminal member carried by said body portion, said fuse link extending out from-the open end of said fuse tube and normally holding said open end against motion with reference to said second mentioned terminal member.

13. A fuse construction comprising a body portion, an expulsion fuse assembly including an insulating fuse tube open at one end, a fuse link having a head closing the other end of said fuse tube, a first terminal member carried by said body portion and pivotally supporting said fuse tube and exerting spring pressure against the head of said fuse link tending to rotate said fuse tube and holding the head in sealing relation to said fuse tube, and a second terminal member carried by said body portion, said fuse link extending out from the open end of said fuse tube and normally holding said open end against motion with reference to said second mentioned terminal member,

the head of said fuse link being movable againstspring pressure under conditions of violent explosion.

. 14. A fuse structure comprising an insulating body portion, a first and a second terminal member carried by said body portion and projecting therefrom, means carried by said terminal members for receiving conductors, an insulating fuse tube having a contact at one end provided with an aperture and pivotally mounted upon the first of said terminal members, the other end of said fuse tube being normally positioned adjacent the second of said terminal members and having an open end, a headed fuse link extending through the aperture in said contact with the head of the fuse link located on the outer side of said contact, means carried by the second terminal member for removably locking the fuse link to said second terminal member to hold said fuse tube in position against rocking motion, and a contact spring electrically connected to said first terminal member and bearing against the head of said fuse link, said spring producing contact pressure and tending to rock said fuse tube towards inoperative position away from said second terminal member.

15. A suspension fuse construction comprising a body portion formed of insulating material and having spaced apertures for the reception of out movement. ALWIN G. STEINMAYER. 

